Vinyl ether end-groups in poly(ethylene glycol)s from the Na2CO3-promoted degradation of 1,3-dioxolan-2-one polymers
✍ Scribed by James J. Harrison; Anatoli Onopchenko; Michael T. Cheng; Carrie Y. Chan
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 207 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0887-624X
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✦ Synopsis
The Na 2 CO 3 -promoted polymerization of 1,3-dioxolan-2-one (I) to afford poly(ethylene glycol) III was reinvestigated. The reaction appeared to involve a nucleophilic attack against the carbonyl and methylene groups of I to afford poly(carbonate) II with poly(ethylene glycol) linkages and ethylene oxide IV as a side product (10 -22%). As the reaction progressed, poly(carbonate) II decreased and poly(ethylene glycol) III increased. Under some conditions, poly(ethylene glycol)s V and VI with vinyl ether terminal groups were formed unexpectedly. The formation of unsaturated products during the polymerization of I/EO (ethylene oxide) has not been reported in the literature. We believe that vinyl ethers were formed from the degradation of poly(carbonate)s and were accompanied by a reduction in molecular weight. The structures of vinyl ethers V and VI were confirmed by hydrogenation of the double bond into the ethyl ether group in VII and VIII, respectively.